• Journal of Animal Science and Technology
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• 제64권3호
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• pp.515-530
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• 2022

Sequence type (ST) 5 methicillin-resistant Staphylococcus aureus (MRSA) with staphylococcal cassette chromosome mec (SCCmec) type II (ST5-MRSA-II) and ST72-MRSA-IV represent the most significant genotypes for healthcare- (HA) and community-associated (CA) MRSA in Korea, respectively. In addition to the human-type MRSA strains, the prevalence of livestock-associated (LA) MRSA clonal lineages, such as ST541 and ST398 LA-MRSA-V in pigs and ST692 LA-MRSA-V and ST188 LA-MRSA-IV in chickens, has recently been found. In this study, clonotype-specific resistance profiles to cathelicidins derived from humans (LL-37), pigs (PMAP-36), and chickens (CATH-2) were examined using six different ST groups of MRSA strains: ST5 HA-MRSA-II, ST72 CA-MRSA-IV, ST398 LA-MRSA-V, ST541 LA-MRSA-V, ST188 LA-MRSA-IV, and ST692 LA-MRSA-V. Phenotypic characteristics often involved in cathelicidin resistance, such as net surface positive charge, carotenoid production, and hydrogen peroxide susceptibility were also determined in the MRSA strains. Human- and animal-type MRSA strains exhibited clonotype-specific resistance profiles to LL-37, PMAP-36, or CATH-2, indicating the potential role of cathelicidin resistance in the adaptation and colonization of human and animal hosts. The ST5 HA-MRSA isolates showed enhanced resistance to all three cathelicidins and hydrogen peroxide than ST72 CA-MRSA isolates by implementing increased surface positive charge and carotenoid production. In contrast, LA-MRSA strains employed mechanisms independent of surface charge regulation and carotenoid production for cathelicidin resistance. These results suggest that human- and livestock-derived MRSA strains use different strategies to counteract the bactericidal action of cathelicidins during the colonization of their respective host species.

• Tuberculosis and Respiratory Diseases
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• 제65권2호
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• pp.91-98
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• 2008

연구배경: 메티실린 내성 황색포도알균은 의료기관 관련 감염 뿐 아니라 지역사회 감염에서도 나타나 이에 저자들은 한 대학병원 중환자실에 입원한 환자의 비강 도말 배양을 통해 MRSA의 의료기관 관련 감염 및 지역사회 감염의 빈도와 분자 역학 및 항생제 내성을 연구하였다. 방 법: 2006년 6월에서 9월까지 건양대학교 병원 중환자실 환자 353명을 대상으로 입실 첫날 비강 도말 배양을 시행하여 MRSA 획득 위험인자에 따라 HA-MRSA와 CA-MRSA로 나누어 Pulsed-Field Gel Electrophorosis (PFGE)로 분류하여 각각의 항생제 내성 검사를 시행하였다. 결 과: 353명 중 비강 도말 배양에서 동정된 MRSA는 42명(11.9%)이며, 동정된 MRSA 중 HA-MRSA는 33명(78.6%), CA-MRSA는 9명(21.4%)이다. PFGE에서 type A에서 type K까지 11형으로 구분하였고 HA-MRSA는 type A (n=9), B (n=7)가, CA-MRSA는 type A (n=2), B (n=2)가 주로 나타났다. 항생제 내성률은 erythromycin, ciprofloxacin에서 HA-MRSA가 CA-MRSA보다 높게 나타났다. 결 론: MRSA의 집락률은 11.9%이며 HA-MRSA의 균주가 CA-MRSA보다 많고, CA-MRSA는 9예로 적은 예지만 PFGE type에서 대부분의 type이 HA-MRSA에서 동정된 type과 같은 경향을 보여 지역사회전파를 시사한다.

• Pediatric Infection and Vaccine
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• 제19권3호
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• pp.111-120
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• 2012

목 적 : 단일 병원 신생아입원실에 입원한 신생아를 대상으로 환자의 임상적 특징에 따른 MRSA 보균율을 알아보고, 그 기원을 추정해 보며, MRSA 보균에 영향을 미치는 요소들을 살펴보고자 하였다. 방 법 : 2008년 1월부터 2011년 12월까지 을지대학교 서울 을지병원 신생아 입원실에 입원하여 MRSA 감시배양검사를 시행받은 1,733명의 신생아를 대상으로 의무기록을 후향적으로 조사하였다. MRSA 감시배양검사는 비강, 서혜부, 직장에서 시행하였고, 퇴원 시까지 매주 반복 시행 하였다. MRSA 감시배양결과에 따라서 보균자와 비보균자로 나누었다. 결 과 : 대상환자 1,733명 중에 415명(23.9%)이 MRSA 보균자였다. 제태기간, 출생체중, 분만 방식, 분만전 산모에게 항생제 투여 여부, 출생장소, 입원전 체류 장소에 따라서 MRSA 보균율에 차이를 보였다(P<0.001). 다변량 검사에서 분만전 산모에게 예방적 항생제를 투여하지 않은 경우가 투여한 경우에 비해서 신생아가 MRSA 보균자가 될 위험도가 2.8배(OR=2.77; 95% CI, 1.88-4.07), 출생장소가 외부인 경우가 본원인 경우에 비해서 2.3배(OR=2.28; 95% CI, 1.17-4.42) 높음을 확인하였다. 결 론 : 신생아 입원환자를 대상으로 한 MRSA 보균율은 23.9%로 상대적으로 높은 보균율을 확인하였다. 환자특성을 고려하여 추정한 HA-MRSA 보균율은 51/511명(10%), CA-MRSA 보균율은 309/858명(36%) 이었다. 본병원 신생아에서 MRSA 보균과 연관된 요인은 산모의 예방적 항생제 사용여부와 출생장소임을 확인하였다.

• Pediatric Infection and Vaccine
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• 제18권2호
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• pp.143-153
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• 2011

목 적 : 황색포도알균의 보균율은 신생아에서 가장 높다고 알려져 있고, 황색포도알균의 보균은 곧 그 균주에 의한 감염증으로 이어질 위험이 높아진다. 본 연구에서는 신생아황달로 입원한 환아에서의 황색포도알균과 MRSA의 보균율을 조사하였고, 신생아황달의 대부분이 모유황달이나 생리적황달임을 감안하여 이를 통해 간접적으로 건강한 신생아의 황색포도알균 및 MRSA 보균율을 추정하고자 하였다. 방 법: 2006년 1월부터 2010년 12월까지 성애병원과 광명성애병원 신생아집중치료실에 황달로 입원한 환아 545명을 대상으로 하였다. 입원 첫날 멸균된 면봉으로 비강과 서혜부를 도찰하여 얻은 검체를 세균배양을 통해 황색포도알균을 동정하고 다시 항생제감수성 검사를 통해 메티실린내성 여부를 판정한 결과를 후향적으로 조사하였다. 결 과:총 545명의 환아가 본 연구에 포함되었고, 이중 318명의 비강과 서혜부에서 황색포도알균이 분리되어 보균율은 58.3%였고 214명의 환아에서는 MRSA가 분리되어 MRSA 보균율은39.3%였다. 또한 분리된 MRSA를 항생제 감수성 결과를 토대로 분석하였을 때, CA-MRSA로 추정되는 균주는 65.7% (142/216), HA-MRSA로 추정되는 균주는 34.3% (74/216)였다. 결 론: 39.3%의 MRSA 보균율로 미루어볼 때, 외부에서 전원되는 신생아를 대상으로 한 MRSA 감시배양검사는 필요하다고 생각된다. 또한, MRSA 균주 중 CA-MRSA 가능성 균주가 65.7%로 높게 나와 이미 지역내산부인과 및 분만실 등에 CA-MRSA 균주가 정착해 있을 가능성이 높다고 생각되며 이에 대한 지속적이고도 정기적인 MRSA 감시배양검사도 필요할 것으로 생각된다.

• 보건의료산업학회지
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• 제6권3호
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• pp.157-169
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• 2012

This survey was undertaken to identify knowledge and performance level of MRSA infection control among medium and small hospital nurses. The subjects of the study were 261 medium and small hospital nurses. The collected data were analyzed by using SPSS WIN 18.0. The total mean values of the knowledge and performance on the MRSA infection control were $9.51{\pm}1.67$ and $2.26{\pm}.47$ respectively. the Knowledge about the general characteristics according to work department, MRSA infection control department presence, MRSA infection control guidelines presence, MRSA infection control education experience, MRSA infection control education method according to the statistically significant differences were observed. The performance about general characteristics according to age, work experience, work department, MRSA infection control department presence, MRSA infection control guidelines presence, MRSA infection control education experience and MRSA infection control education methods according to the statistically significant differences were observed. It is having sufficient various facilities, to enhance nurses knowledge about management of MRSA infection. If the continuous education of professional infection control is offered, it contributes to protect MRSA infection in the medium and small hospitals.

• 대한간호학회지
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• 제33권6호
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• pp.686-692
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• 2003

Purpose: To assess the effect of handwashing improving program and MRSA carrier detection program on MRSA(methicillin resistant Staphylococcus aureus) infection rate in a intensive care unit. Method: The intervention was Nosocomial Infection(NI) control program consisted of hand washing improving program and identification and treatment of MRSA carrier. Data on the NI and MRSA infections were collected by an infection control nurse based on the definition of CDC. MRSA infection rates were calculated by the number of MRSA infection per 100 admissions or 1,000 patients-days. The difference of MRSA infection rates between pre and post intervention was tested by Chi-square at =.05. Result: MRSA infection rates 3.0% or 3.2 per 1,000 patient-days at the pre, 4.6% or 3.7 per 1,000 patient-days at the post, and the differences were not statistically significant (p=.411, p=.769 respectively). Conclusion: The handwashing improving program and MRSA carrier detection program was not effective in reducing the Nosocomial Infection(NI) or MRSA infection rates. It is recommended further studies with a longer intervention and follow-up period.

• Journal of Microbiology
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• 제44권3호
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• pp.336-343
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• 2006

We compared the antimicrobial resistance and clonal relationships among the community-acquired (CA) and hospital-acquired (HA) methicillin-resistant Staphylococcus aureus (MRSA) strains that were isolated from blood cultures in a university hospital over a 4-year period. A total of 131 MRSA isolates, including 28 CA-MRSA and 103 HA-MRSA strains, were identified; antimicrobial susceptibility testing indicated that the CA-MRSA isolates were more susceptible to erythromycin (21 % vs 6% ; P=0.02), clindamycin (46% vs 12%; P<0.01), ciprofloxacin (43% vs 11%; P<0.01), and gentamicin (43% vs 6%; P<0.01) than were the HA-MRSA isolates. Pulsed-field gel electrophoresis (PFGE) typing and antimicrobial resistance profiles separated the 20 CA-MRSA isolates into 14 and 10 different patterns, respectively, and the 53 HA-MRSA isolates were separated into 24 and 7 different patterns, respectively. Twenty-one (40%) of the 53 HA-MRSA isolates belonged to two predominant PFGE types, and most of them showed multi-drug resistant patterns. Four (20%) of the 20 CA-MRSA and 10 (19%) of the 53 HA-MRSA isolates fell into two common PFGE patterns, and each of them showed the same multi-drug resistant pattern. This study suggests that, although the CA-MRSA blood isolates showed diverse PFGE and antimicrobial resistance patterns, some of these isolates may have originated from the HA-MRSA strains.

• Pediatric Infection and Vaccine
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• 제16권1호
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• pp.1-5
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• 2009

Methicillin-resistant Staphylococcus aureus (MRSA), a leading cause of nosocomial infections, has been increasingly recognized in communities of the United States. This article will review the clinical spectrum and treatment of MRSA infections in children in the context of recent epidemiological changes of MRSA infections. In general, community-associated (CA) MRSA most frequently causes skin and soft tissue infections and has an increased association with invasive infections, particularly pneumonia and musculoskeletal infections. Hospital-associated (HA) MRSA strains tend to be associated with bloodstream infections, pneumonia, and surgical site infections. Different from the United States, CA-MRSA infections are not common in Korea (only 5.9%); however, there are some CA-MRSA clones that are different from HA-MRSA clones in Korea and from CA-MRSA clones in other countries. The treatment of MRSA infections should be guided by antimicrobial susceptibility testing, the site of infection, and the infection severity. Vancomycin is the treatment of choice for invasive MRSA infections. Other agents such as trimethoprim-sulfamethoxazole, clindamycin, linezolid, quinupristin-dalfopristin, and daptomycin have been used for some conditions.

• 대한의생명과학회지
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• 제27권4호
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• pp.195-207
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• 2021

Methicillin-resistant Staphylococcus aureus (MRSA) is a bacterial pathogen capable of causing human diseases, such as soft tissue infection, bacteremia, endocarditis, toxic shock syndrome, pneumonia, and sepsis. Although the incidence rate of diseases caused by MRSA has declined in recent years, these diseases still pose a clinical threat due to their consistently high morbidity and mortality rates. However, the role of virulence factors in staphylococcal infections remains incompletely understood. Methicillin resistance, which confers resistance to all β-lactam antibiotics in cellular islets, is mediated by the mecA gene in the staphylococcal cassette chromosome mec (SCCmec). Differences in SCCmec types and differences in their sizes and structures serve epidemiological purposes and are used to differentiate between hospital-associated (HA)-MRSA and community-associated (CA)-MRSA. Some virulence factors of S. aureus are also providing a distinction between HA-MRSA and CA-MRSA. These factors vary depending on the presence of toxins, adhesion, immune evasion, and other virulence determinants. In this review, we summarized an overview of MRSA such as resistance mechanisms, SCCmec types, HA- and CA-MRSA, and virulence factors that enhance pathogenicity or MRSA epidemiology, transmission, and genetic diversity.

• 대한의생명과학회지
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• 제10권3호
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• pp.309-315
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• 2004

Methicillin resistant Staphylococcus aureus (MRSA) is one of the most common nosocomial pathogens. Many hospitals are facing the problems which they have to use expensive antibiotics and suffer from long term hospital study of patients due to MRSA. This study is to survey MRSA nasal colonization of patients and doctors, and to investigate the mode of transmission of MRSA by pulsed field gel electrophoresis (PFGE) and then use these data to prevent further spread of cross infection and reduce nosocomial infection. Subjects of this study were 201 patients with MRSA infection at an university hospital in Busan from Sept. 1997 to Aug. 1998. Bacterial genotypes of MRSA strains isolated from nares and wound of patients (14 cases) and nares of doctors (8 cases) were analyzed by PFGE. Nasal cultures of 20 I patients for detecting nasal colonization of MRSA were performed and incidence rate of nasal colonization was 40％ (80/201). Among 201 patients MRSA were acquired from hospital in 140 (70％) patients and were acquired from community 61 (30％) patients. Among 14 pairs of MRSA from colonized or infected sites and anterior nares, DNA patterns of 10 pairs (71.4％) were equal. 86％ (12/14) MRSA strains isolated from patients and 12.5％ (1/8) MRSA strains isolated from doctors show same pattern. DNA patterns were changed in some doctors after nasal oint. Treatment. It could be inferred that the most sources of MRSA in hospital are the endemically existing MRSA. Therefore, we believe that it would be necessary to control MRSA nasal colonization of the patients and the related medical teams to reduce the medical cost and to improve the efficacy of medical cares.